Furnace arch



Patented Mar. 15, 1932 UNITED' STATES PATENT OFF SIDNEY THURSBY, OF LONDON, ENGLAND, ASSIGNORTO Ha WINDSOR & COMPANY V LIMITED, OF LONDON, ENGLAND 1 FURNACE ARCH.

Application filed August 1, 1930, Serial No. 472,350, and in Great Britain April 29,1930;

It has been found that in furnaces for boilers and the like having a sprung arch, the scouring effect of the hot gases erodes not only the upper courses of the j ainb walls, but also the side courses of the arch, and in severe cases, even the skewbacks themselves. Erosion of the jamb walls is not of great moment, as it is not a matter of difficulty to reline those walls, but erosion of the side courses of the arch or of the skewbacks is a serious disadvantage as replacement of those courses or skewbacks is a lengthy and expensive procedure. The object of the present invention is to prevent erosion of the side courses of the arch or of the skewbacks and to this end the upper courses of the jamb walls are replaced by blocks of refractory material formed with projections adapted to underlie the side courses of the arch. Such blocks are built into the amb walls of a furnace for the whole or part of the length of the arch and may be removed and replaced, when scoured,without serious difliculty and Without interfering with, or impairing the stability of, the arch.

The dimensions of that part of the block which replaces the upper courses of the jamb wall (i. e. the block exclusive of the projection) should be such that its diagonal in a vertical plane transversely of the furnace is so much greater than its height as to prevent risk of said block tipping inwards even after its thickness in said transverse direction has become reduced by erosion. The width of the supporting base of the block is of a considerable extent when compared with the height of the corbel block, and this makes the diagonal in the vertical plane transversely of the furnace much greater than the height of the block. This wide base makes the block very stable, and it prevents the block tipping inwardly even after it has become considerably reduced by erosion by the hot furnace gases.

The projection from the block may be from the upper part of that face thereof which is to be directed inwards but preferably it extends from the whole of said face.

In the accompanying drawings, illustrating one form of the invention, Figure l is a transverse sectional elevation of part of a boiler furnace and Figure 2 is a section on the line 22, Figure 1.

Blocks a a of refractory material are built into the jamb walls I) b andare formed with projections a 4 each extending from the whole of that face of the block which is directed inwardly, and underlying the side courses 0 c of the sprung arch 0, which courses abut against the skewbacks cl cl of 60 usual type.

The blocks a a; may be built into the jamb walls as far as the innermost edge of the skewbacks (Z (Z or partially or completely to underlie said skewbacks so that protection from the hot gases is afforded to both the side courses 0 c and the skewbacks d d themselves.

In the case of a stepped sprung arch the blocks a a if desired may be of different sizes in order to fit securely within the different heights of the jamb walls and the projections under-lying the side courses of the arch may be carried further inwardly (i. e. towards the centre of the arch) as the hottest parts of the furnace are approached i. e. towards the rear thereof or towards the highest arch of the steps.

I claim 1. In a furnace arch for boilers, or the like, provided with jamb supporting walls, a construction in which the upper courses of the jamb walls beneath the level of the junction of the arch with the said jamb walls are replaced by blocks of refractory mate: rial; the said blocks of refractory material including extending projections adapted to underlie the inner exposed faces of the arch.

2. A furnace arch construction as defined in claim 1 in which the blocks of refractory material are built into the j amb walls along the length of the arch and are adapted, when scoured, to be easily removable and replaceable without impairing the stability of the arch. p 95.

8. A furnace arch as defined in claim 1 in which the block of refractory material is provided with a relatively wide base as compared with its height, so that a diagonal in a vertical plane, is materially greater than its height this proportioning of the block preventing the possibility of the block tipping inwardly due to erosion by the hot furnace gases when its thickness has been reduced in the transverse direction.

4. A furnace arch as defined in claim 1 in which the projection adapted to underlie the inner exposed faces of the arch projects from the longitudinal vertical plane passing through the inner edge of the block.

m 5. A furnace arch as defined in claim 1 in which the projection adapted to underlie the inner exposed faces of the arch extends from the upper part of the block and projects inw wardly.

SIDNEY THURSBY. 

